well, you can't expect FBS to be crystal clear since it is serum. I have received FBS which had debris, but they didn't affect the growth of my cells. However, I'm not sure what debris you are seeing in there. Have you checked the expiry date? which company is it from?

I just recently moved to this new lab, and since I am the only cell culture-ist I want to make sure everything is spot on! This has been a question in my mind for a while now and whilst I always thought these "bits" were standard for serum, I just wanted to try and clear any doubts from my conscience.

For the record, our FBS is from Fisher/Lonza and was ordered only last week.

Yes, sera contain debris, I don't know why really. The not yet heat inactivated sera contain more debris though.
I use horse serum for my CHRF cells, they like it more than FBS, but it contains a lot of debris. I filter my serum before adding it to the media or freezing it, this removes most debris. Filtering may affect the proteins in the serum, but it works fine with my cells. It also removes any contamination if it was there.

It was just one of those niggling little doubts in my mind that I needed to clear up. I was 99% confident that my media wasn't contaminated as it remained "clear" and my cells remained "helathy", but your answers have put my mind to rest a little.